Here are the correct forms of the words in the brackets:

1. The gas from the chemical factory was **extremely** harmful. (EXTREME)
2. Pablo Picasso was a very **creative** artist. (CREATE)
3. It’s forbidden to destroy **historic** buildings. (HISTORY)
4. They are members of an international **organization**. (ORGANIZE)
5. Last Sunday afternoon, the students walked up the **mountainous** mountain to visit the shrine of a Vietnamese hero. (MOUNTAINOUS)
6. We can protect the environment by **reducing** air pollution. (REDUCE)
7. Wearing uniforms encourages students to be **proud** of their school. (PRIDE)
8. Vietnam is an **agricultural** country. (AGRICULTURE)
9. Nam is very **interested** in computers. (INTEREST)
10. He was punished for his **laziness**. (LAZY)